# US 10,770,569 B2 · Semiconductor device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,770,569 B2 - Document ID: US10770569B2 - Status: Granted - Kind: B2 - Application number: 16/436,753 - Filed: 2019-06-10 - Published: 2019-10-10 - Granted: 2020-09-08 - Earliest claimed: 2015-03-23 - Assignees: Taiwan Semiconductor Manufacturing Company, Ltd. - Applicants: Taiwan Semiconductor Manufacturing Co., Ltd. - Inventors: Wei-Yang Lo; Shih-Hao Chen; Mu-Tsang Lin; Tung-Wen Cheng - Web page: https://patentgrep.com/patent/US10770569B2 ## CPC - H10D 30/024: {of fin field-effect transistors [FinFET]} - H10D 30/62: Fin field-effect transistors [FinFET] - H10D 30/6213: {having rounded corners} - H10D 30/6217: {having non-uniform gate electrodes, e.g. gate conductors having varying doping} - H10D 62/151: {of IGFETs (of IGFETs having LDD or DDD structure H10D30/601; of thin film transistors H10D30/6713)} - H10D 64/021: {using multiple gate spacer layers, e.g. bilayered sidewall spacers} - H10P 50/242: {of Group IV materials} - H10P 50/642: {Chemical etching} - H10D 30/797: {being in source or drain regions, e.g. SiGe source or drain} - H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract A transistor includes a semiconductive fin having a channel portion, a gate stack over the channel portion of the semiconductive fin, source and drain structures on opposite sides of the gate stack and adjoining the semiconductive fin, and a sidewall structure extending along sidewalls of a body portion of the source structure. The source structure has a curved top, and the source structure has a top portion protruding over a top of the sidewall structure. ## Claims ### Claim 1 A transistor, comprising: a semiconductive fin comprising a channel portion; a gate stack over the channel portion of the semiconductive fin; source and drain structures on opposite sides of the gate stack and adjoining the semiconductive fin, wherein the source structure has a curved top; and a sidewall structure extending substantially along sidewalls of a body portion of the source structure, wherein the source structure has a top portion protruding over a top of the sidewall structure. ### Claim 2 (depends on 1) The transistor of claim 1, wherein the top portion of the source structure has a first surface segment extending upwards and outwards from the top of the sidewall structure, and the first surface segment of the top portion of the source structure is curved. ### Claim 3 (depends on 2) The transistor of claim 2, wherein the top portion of the source structure has a second surface segment interconnecting the first surface segment of the top portion of the source structure and the curved top of the source structure, and the second surface segment of the top portion of the source structure is substantially flat. ### Claim 4 (depends on 1) The transistor of claim 1, wherein a surface segment of the top portion of the source structure extends from the top of the sidewall structure to the curved top of the source structure and is curved. ### Claim 5 (depends on 1) The transistor of claim 1, wherein the source structure comprises a p-type dopant. ### Claim 6 (depends on 1) The transistor of claim 1, wherein the curved top of the source structure has a radius of curvature ranging from about 5 nm to about 20 nm. ### Claim 7 A transistor, comprising: a semiconductive fin comprising a channel portion; a gate stack over the channel portion of the semiconductive fin; and source and drain structures on opposite sides of the gate stack and adjoining the semiconductive fin, wherein each of the source and drain structures has a side surface, the side surface of each of the source and drain structures has a first segment extending upwardly from a sidewall of the semiconductive fin, a second segment extending upwardly from the first segment and outwardly in a direction from a bottom to a top of the second segment, and a third segment extending upwardly from the second segment and inwardly in a direction from a bottom to a top of the third segment, and the second segment of the side surface of each of the source and drain structures is curved. ### Claim 8 (depends on 7) The transistor of claim 7, wherein the third segments of the side surfaces of the source and drain structures are substantially flat and respectively inclined towards tops of the source and drain structures. ### Claim 9 (depends on 7) The transistor of claim 7, wherein the third segment of the side surface of each of the source and drain structures is curved. ### Claim 10 (depends on 7) The transistor of claim 7, wherein each of the source and drain structures has a curved top. ### Claim 11 (depends on 7) The transistor of claim 7, further comprising: a sidewall structure extending substantially along sidewalls of a body portion of the drain structure, wherein the drain structure has a top portion protruding over a top of the sidewall structure. ### Claim 12 (depends on 11) The transistor of claim 11, wherein the second segment of the side surface of the drain structure extends from the top of the sidewall structure. ### Claim 13 (depends on 11) The transistor of claim 11, further comprising: an isolation structure around a lower portion of the semiconductive fin, wherein a bottom surface of the sidewall structure is over a top surface of the isolation structure. ### Claim 14 (depends on 13) The transistor of claim 13, wherein a bottom surface of the drain structure is lower than the bottom surface of the sidewall structure. ### Claim 15 (depends on 11) The transistor of claim 11, wherein the top portion of the drain structure has a portion wider than the body portion of the drain structure. ### Claim 16 (depends on 11) The transistor of claim 11, wherein the sidewall structure is in contact with the drain structure. ### Claim 17 A transistor, comprising: a semiconductive fin comprising a channel portion; a gate stack over the channel portion of the semiconductive fin; source and drain structures on opposite sides of the gate stack and adjoining the semiconductive fin, wherein the source structure comprises a p-type dopant; and a sidewall structure extending substantially along sidewalls of a body portion of the source structure, wherein the source structure has a top portion protruding over a top of the sidewall structure. ### Claim 18 (depends on 17) The transistor of claim 17, wherein the top portion of the source structure has a curved top. ### Claim 19 (depends on 17) The transistor of claim 17, wherein the top portion of the source structure has a first substantially flat surface segment, a second substantially flat surface segment, and a curved surface segment interconnecting the first substantially flat surface segment and the second substantially flat surface segment. ### Claim 20 (depends on 17) The transistor of claim 17, wherein an entire surface of the top portion of the source structure is curved.